Wall for dams, barriers, protection-walls, and reservoir-walls, and the like.



PATENTED MAY 22, 1906. P. HENNEBIQUE.

, PROTECTION WALLS, AND RESERVOIR WALLS,

WALL FOR DAMS, BARRIERS AND THE LIKE.

APPLICATION FILED FEB.7.1903.

4 SHEETS-SHEET 1.

'INVENT-OR' ATTOR N 5V5 No. 821,037. PATENTED MAY 22, 1906.

P. HBNNEBIQUB.

WALL FOR DAMS, BARRIERS, PROTECTION WALLS, AND RESERVOIR WALLS,

AND THE LIKE.

" PPLI TION I ..1

A 0A FILED BB 7 903 SHEETS-SHEBT 2.

Mimi

WITN 51652-5 No. 821,037. PATENTED MAY 22, 1906. P. HENNEBIQUE. WALL FOR DAMS, BARRIERS, PROTECTION WALLS, AND RESERVOIR WALL,

AND THE LIKE.

APPLICATION FILED FEB. 7.

'l 4 SHEETS-SHEET 3.

iNVELN'FOR M mm 7% ATTORN 5Y5 N0. 821,037- PATEN'TED MAY 22, 1906.

P. HBNNEBIQUE. I BARRIERS, PROTECTION WALLS, AND RESERVOIR WALLS,

WALL FOR DAMS,

AND THE LIKE.

AAPPLIOA'TION FILED FEB.'I,1903.

4 SHEETS-SHEET 4.

My yE/v or? W/T'NE 66 E6 Wop/V5345 UNITED STATES FRANCOIS HENNEBIQUE, OF PARIS, FRANCE.

WALL FOR DAMS, BARRIERS, PROTECTION-WALLS, AND RESERVOIR-WALLS, AND THE LIKE.

PATENT ()FFICE.

Patented May 22, 1906.

Application filed February 7, 1903. Serial No. 142,400.

To all whom, it may concern:

Be it known that I, FRANQOIS HENNE BIQUE, residing at 1 Rue Danton, Paris, France, have invented certain new and useful Improvements in Walls for Dams, Barriers, Protection-Walls and Reservoir-Walls, and the Like, of which the following is a full, clear, and exact specification.

The accumulation of masses of water,

Sometimes as much as ten, twenty, and even thirty millions of cubic meters, for town-reservoirs, irrigation-canals, and the like may become very dangerous if the dikes or dams which retain them are not so constructed as to be absolutely safe. It is owing to this lack of absolute security that dams have given way, causing enormous disaster. The breakdown of large masonry dams is almost always due to the formation of fissures .resulting from the very slight resistance of mortar to tensional strain.

By substituting cement or beton strengthened with a metallic framework suitably arranged so as to resist all tensional strains (strains proper or strains produced by shearing or bending action) for ordinary masonry this cause of danger will be absolutely removed. Cement strengthened with iron framework is more expensive than masonry. Therefore in order that the walls of reservoirs made of such strengthened cement shall not be more expensive or even, if possible, cheaper than those of ordinary masonry the walls must be able to be made thin. Here, however, a difficulty is encountered. When the pressure exceeds a dozen meters, (as experience with conduits of strengthened cement has proved,) the walls of such strengthened cement are not sufliciently water-tight,

and there is no certainty of obtaining sufficient water-tightness even with considerablyincreased thickness.

The invention which forms the subject of the present application enables these difficulties to be overcome by the following means: Behind the wall against which the water comes I arrange others of regularlydecreasing height as though to form the steps of a cascade. Then by means of suitably-arranged apparatus 1 cause the compartments thus formed to be always filled with water when the reservoir is full, and when it is emptying itself the differences of level of the water in the various compartments shall not exceed the height of the steps. Under these conditions the maximum effective pressure on these walls, which is only due to the difference of level of the water on the two sides of the wall, will vary in an inverse ratio to the number of these walls, and consequently may be reduced as much as may be considered necessary for insuring the requisite water-tightness. On the other hand, by adopting a cylindrical form concave against the stream, in section horizontal, in an arc of a circle or in certain cases semicircular, these walls will be found under the same conditions to act the same as those of reservoirs of small ing concave cylindrical continuous and in-' clined multiple walls arranged in steps. Fig. 2 is a horizontal section on the line A B of Fig. 1, showing three piers. Fig. 3 is a vertical section on the line G H of Fig. 4, and Fig. 4 is a horizontal section on the line E F of Fig. 3 of a protection-wall in front of an existing dam having continuous cylindrical multiple walls arranged in steps. Fig. 5 is a diagrammatic plan view of a polygonal reservoir having a single wall formed in semioylinders of cement strengthened with a framework. Fig. 6 is a diagrammatic plan view of a circular reservoir of large diameter having multiple semioylindrical walls in steps. Fig. 7 is a diagram of a cylindrical reservoir having multiple walls in steps. Fig. 8 is a vertical section on the line C D of Fig. 9 of a reservoir-wall for a dam or reservoir proper having semioylindrical vertical walls in steps. Fig. 9 is a horizontal section on the line A B of Fig. 8. Figs. 10 and 11 are similar views to Figs. 3 and 4 of a protection-wall the sections of the walls of which are semicircular. Fig. 12 is a vertical section on the line K L of Fig. 13 and on the line C D of Fig. 2 of cement-strengthened walls, showing the metallic framework. Fig. 13 is a horizontal section on the line I J of Fig. 12 and on the line A B of Fig. 1 of the same walls and piers, showing the metallic framework. Fig. 14 is a vertical section on line C D of Fig. 2, show ing safety-valves and vibrating valves.

The reservoir-wall (shown in Figs. 1 and 2) is divided. into bays by a certain number of piers a, (spaced at six meters apart, for instance.) On these piers the water-tight wall I) c (1 rest and are cemented. These walls I), c, and 01 decrease in height from the up stream side to the rear, (for instance, thirty meters, twenty meters, and ten meters in height, respectively.) Owing to apertures formed in the walls and closed by suitablyloaded valves h, the difference in the level of the water on the upstream side and the downstream side of each wall will never be greater than the height of the steps, (say ten meters.)

The walls are cylindrical in form, concave toward upstream, in section in an arc of a circle. They are of cement strengthened with a framework of minimum thickness. Their metallic framework, as shown, Figs. 12 and 13, is composed, like that of the cylindrical part of reservoirs of small capacity, of cement strengthened with a framework. The resistance to the pressure of the water is insured by barsy' acting against tensional strain, and the maximum strain which they support (neglecting the resistance of cement itself to tensional strain) is known by static. The object of the strengthening-bars 7c is more particularly to prevent the cracking of the cement in the intervals between the bars and also to distribute on several bars accidental strains, such as those produced by shocks. The bars jare prolonged beyond opposite face of the pier into the neighboring bay and ended in a hook form I, as shown, Fig. 13. By giving to bars 7' the maximum length which iron-works can furnish the same bar will form part of two or three bays, which will diminish the quantity of metal employed for the brazing and which will play the part of cover-joints in metallic constructions. Care must also be taken to cross the joints from bay to bay. Water-tightness of said walls of cement strengthened is assured because the effective pressure of water, owing to the counter pressure produced by the water on the downstream side of the walls, will not exceed ten meters as in reservoirs of small capacity of cement stren thened.

The cylindrical walls c d are cemented to the piers a of strengthened beton, against which they rest, transmitting to them the pressure of the water.

By giving the cylindrical walls a considerable inclination for instance, thirty d egrees from the vertical-complete security from the point of view of the stability of the work will be obtained, because then instead of tending to overthrow the wall, as in actual vertical dams, the pressure of the water will itself fix the dike to the ground, which is a very important point.

In the massive masonry dikes or dams hitherto employed it is the weight of the masonry which maintains it in place, in spite of the horizontal pressure of the water, which skips? tends to throw it down. The action of this weight, however, may be insufficient if subpressures are produced at the base of the solid mass or in its interior by reason of fissures in the masonry. This danger has been endeavored to be obviated by means of protection or guard walls, but without any certainty of obtaining the result desired, because it is always to be feared that water under pressure may pass under their foundations.

With strongly-inclined walls I) c d the normal pressure of water, which is transmitted to the piers, helps by its vertical pressure added to the weight of the dyke or dam to fix the latter to the ground. This vertical pressure of the water on the inclined walls replaces the excess of dead-weight of massive masonry dikes or dams.

As may be seen in Fi 1, the resultant of the water-pressure an the weight of the dam forms a smaller angle from the vertical than the angle of friction. Therefore in spite of the relatively light weight ofthe dam its stability is insured without its being necessary to count on the anchorage of the piers. This stability is due to their own weight increased by the vertical water-pressure, and, further, it cannot fail, because contrary to what happens to solid dams the subpressures cannot upset the equilibrium. Indeed, as filtered water may flow away freely between the piers there cannot be subpressure except in the upstream part of their foundations, and consequently on a very slight surface relatively to the surface of the cylindrical Walls, which transmit to the piers all the water-pressure that they are subjected to.

The resultant passing approximately through the middle of the base, the piers and their foundations will be compressed along all their length, which condition is favorable to the stability, because at no point is there a tendency to lift, which would facilitate leakage. It suflices to give the foundations of the piers a footing in proportion to the resistance to compression of the ground. Care must also be taken to cut the bottom of the excavation in steps 9 9, so as to o pose slipping, although this is not to e feared, seeing that one part, the resultant, forms a smaller angle to the vertical than the an le of friction and that, on the one hand, dams are never erected on sliding ground, the only one on which the angle of' friction should be of smaller value.

It must be pointed out that slight settling of piers for any cause, even in consequence of oscillations of the ground in countries subject to earthquakes, will not modify the conditions of working of the walls of cement strengthened, and consequently can at the most only produce very fine fissures in the cenaent, which soon become stopped up by mu 0 To sum up, the pressure of the water tends to fix the dam tothe soil, and in order that this stability may be insured it is sufficient for the ground to have a very ordinary resistance to compression and while being tight not to be slippery. These conditions are easily realized, and consequently a wider latitude is allowed for choosing the situation of the dam or barrier than is the case with massive masonry dikes.

The piers a, Fig. 13, are only subjected to compression strains, either those which are transmitted to them by the bars or those resulting directly from the pressure of the water on their heads. Their metallic framework may therefore be very light, seeing that its sole object is to prevent their accidental fissuring in consequence of variations of temperature. In the neighborhood of the downstream face, however, the general effects of compression are not equilibrated as they are in the interior of the pier and at its base by the reactions of the adjacent cement or beton or of the ground, and therefore the beton in said part will be subjected to a shearing action. This shearing action will produce secondary horizontal traction strains, which the beton may be made to resist by strengthening it with horizontal bars 1", Fig. 31, terminating in hooks s toward the upstream side, so as to anchor them in the most resisting part of the pier. These bars offer no inconvenience, because they may be stopped at a sufficient distance from the water-face, and consequently there is no need to fear that they will facilitate leakage.

At the height of the steps the piers a are buttressed by floors or platforms of cement strengthened with metal-work m n, Fig. 1, which prevent their bending or giving under the pressure of the water and further facilitate the supervision of the work and the water manipulations.

It is indispensable that for each partitionwall the difference of height between the level above and the level below should never exceed the height of the steps which reaches in practice a maximum of ten meters, for beyond that the thin partition-Walls of reinforced cement might possibly not present a sufficient tightness. Most frequently the differences in level will be maintained within the desired limits by the very function of the reservoir. However, in any case the automatic action of the valves (shown in detail in Fig. 14) will bring this condition without requiring the intervention of watchmen.

The height of the steps must not exceed the height of the water corresponding to the pressure up from which one ceases to be certain of the impermeability of the thin walls of reinforced cement. In practice, this pressure being of ten meters, the steps may be raised to a maximum height of ten meters. In order to remain within this limit of ten above dam, are provided.

meters, it suffices to form the walls of the dam of a number of partition-walls being equal to the figure denoting the tens of me ters of the damming height plus one unit. For example, three partition-walls will be necessary for a dam of tWenty-seven-meters height, and this will give steps being nine meters highthat is to say, three walls, the highest of twenty-seven meters, the following one of eighteen meters, and the last one of nine meters. The height of the steps being thus determinedfor instance, nine meterssuch arrangements must be made that the difference in the level of the water facing the partition-walls from above and that facing them from below will never exceed the height of nine meters. This should be absolutely insured and without the dam watcher having to intervene, owing to the water-gates, by means of safety-valves, as will be shown.

Similar compartments in all the bays communicate by apertures t, Figs. 1 and 2, formed in the piers (L. Then it will suffice to arrange in each of the walls I) and c of one of the bays an aperture f, closed by a valve h, opening from upstream downstream. Normally this valve h (detailed in Fig. 14) is kept closed by an eccentric weight p-for instance, a block of cast-iron. This weight is retained by a brace so, and it acts in center of the safety-valve 71 by a rod *6, attached by nuts. The weight p is such that the valve shall open as soon as the difference of level of the upstream water beyond the downstream water exceeds the limit which is set for it, (in the present instance, say ten meters.) Immediately the down level has risen to ten meters relative to the above level the weight 19 will close the valve.

If the lever-arm of the weight 29 is one meter in length, this ball should weigh only two hundred kilograms for a valve of 0.30 meters by 0.20 meters, and this aperture would seem to be quite sufficient for providing against all eventualities; but if the barrier or dam be very long several bays might be provided with valves.

The valves open automatically when the difference of level exceeds the height for which the weight 2) has been calculated, and this opening will be limited because the weight when in the position shown in dotted lines at 12 will have greater leverage.

Finally, if for any cause the level of the water should lower more on the above side of a wall than on the below side to prevent said wall being subjected to compression for which it is not constructed. a second series of openings closed by vibrating valves 0, Fig. 14, opening from the below dam side to the There openings may be of very small dimensions, and the pressure of the water normally stronger 011 the above dam side will suffice to alone keep the corresponding valves closed.

The system of reservoir-walls having cylindrical concave multiple walls in steps, which I have just described, is applicable to dams whatever their height may be. The number of the walls will be increased proportionate to the height. heights below a dozen meters, only one wall would be required. On the other hand, the system is applicable to any form of dam, whether straight or curved. With a closed perimeter a proper reservoirwill be obtained of very large capacity. In this case it is generally preferable to replace the cylindrical walls inclined in an extended arc of a circlesection by vertical cylindrical Walls of semicircular section, Figs. 8 and 9; but then in order to replace the vertical component of the water-pressure which becomes null the piers prolonged upstream will be anchored in the ground. The multiple walls of cement strengthened and their metallic framework are analogous to those hereinbefore described and shown, Figs. 12 and 13.

The perimeter of the reservoir might be of any suitable form, curved, Fig. 6, or polygonal, and in this latter case irregular if the configuration of the ground requires it, Fig. 5. The piers will then be traced normally at the sides of the perimeter. Those parts which reach the summit of the polygon will be connected by Walls of circular tangential section, but having more than a semicircumference. This will be the sole difference.

When there is lack of space or where it is desired to have a high pressure of water, the reservoir may be of great height by employing the arrangement of multiple walls in steps. (Shown in Figs. 6 and 8.)

When there is no very large quantity of water to be stored, recourse might still be had to cylindrical reservoirs of strengthened cement, which would be less expensive; but the use of multiple walls would enable them to be made of greater height in order to have the water under higher pressure, Fig. 7, or a much larger diameter, and consequently a greater capacity. If the height of the steps be constant, the section of the directing-bars must increase from wall to wall proportionately to the radius of the walls, or inversely, if it is desiredalways to have the same metallic framework the height of the steps must be caused to decrease in inverse ratio to the radius of the walls. Theoretically by sufficiently diminishing the height of the steps, so as to have only very slight effective pressures, the diameter of the reservoir and its height might be increased indefinitely but in practice the cost of the cylindrical reservoir would become excessive by reason of the large number of walls. actual maximum dimensions of the cylindrical reservoirs in strengthened cement are to be much exceeded it is preferable in each particular case to seek the most economical As a particular instance for low Therefore when the solution, Whether a cylindrical reservoir with multiple walls or a reservoir having semicylindrical walls, which may be multiple, if required.

Finally, the system is very applicable to the construction of guard or protecting walls intended to protect existing dams from leakage, which in the long run bring about their destruction. The piers, Fig. 3, then rest against the solid masonry of the dam, and it is preferable to place them near together in order to diminish the force of the pressure which they transmit to the masonry, which varies in inverse ratio to their number. According to whichever appears the most suitable, wateretight walls shall have a section of an extended arc of a circle, Fig. 3, or semicircular section, Fig. 9.

I may add that the form of the walls in an arc of a circle or semicircular and concave toward upstream with the highest pressure on the upstream sidethat is to say, on the interior of these wallsis a form of stable equilibrium, and that consequently accidental deformations, which must also be fore seen and which may result from the shock of waves or floating bodies or even malicious attempts, will not tend to increase or spread and will remain local.

The semicircular section offers in addition the advantage that each bay is in equilibrium by itself and that the walls only transmit to the piers stresses directed along their axis, which condition is very favorable for stability.

It may finally be remembered that with strengthened cement fissures are not to be feared, while they are the cause of the ruin of the ordinary masonry barriers or dams. On the other hand, as the walls in contact-with water are only subjected to tension and the piers to compression, the system is constituted of true solids of equal resistance, which reduces to a minimum the cube of materials, though it increases the security, since the conditions under which the materials work are perfectly determined.

The small quantity of material employed has also the advantage of allowing a great rapidity of construction, and as, on theother hand, the setting of the cement is very rapid and it is even of advantage to keep it moist the retention of water may be commenced immediately, thus allowing of greater rapidity of utilization than in the case of ordinary masonry barriers or dams.

I declare that what I claim is- 1. In dams, guard-walls and reservoirs proper, the combination of continuous thin and water-tight cylindrical walls concave toward upstream, said walls consisting of cement strengthened with a metallic framework, resting on and attached. to piers of strengthened beton, buttressed by platforms of strengthened cement, substantially as de' scribed.

IIO

2. In dams, guard-walls and reservoirs proper and cylindrical reservoirs constructed of cement and beton strengthened, the combination of multiple walls in steps decreasing in height from above dam downstream said walls forming successive compartments with apparatus adapted to hold water at such heights that its level shall always be lower on the reverse than on the dam side of any of the walls and that the difference of level above and below every Wall shall never exceed the height of the steps, substantially as described.

3. In the multiple walls of reservoirs of cement strengthened such as hereinbefore described the combination of safety-valves opening downstream and loaded with weight adapted to preserve the difference in the level above and below every wall within a fixed limit, substantially as described.

4. In the multiple Walls of reservoirs of cement strengthened such as hereinbefore described the combination of vibrating valves opening from'the downstream toward the upstream normally maintained closed by the pressure of water adapted to preserve the level higher abovethan down, substantially as described.

In witness whereof I have hereunto set my hand in presence of two witnesses.

FRANQOIS HENNEBIQUE. Witnesses:

EMILE BERT AUGUSTUS E. INGRAM. 

